Qt下使用OpenGL（9）-根据NeHe的教程改写的

#ifndef NEHEWIDGET_H
#define NEHEWIDGET_H

#include <QtOpenGL/QGLWidget>
//#include "ui_nehewidget.h"

#include <qgl.h>

const GLuint num=50;
typedef struct {
int r,g,b;
GLfloat dist,angle;
}stars;

class nehewidget : public QGLWidget
{
Q_OBJECT

public:
nehewidget(QWidget *parent = 0,bool fs=false);
~nehewidget();

protected:
void initializeGL();
void paintGL();
void resizeGL(int w,int h);

void keyPressEvent(QKeyEvent *e);
void loadGLTextures();
void timerEvent(QTimerEvent *);

bool fullscreen;
GLfloat zoom;
GLuint texture[1];
GLfloat spin,tilt;
GLuint loop;

bool twinkle;
stars star[num];
};

#endif // NEHEWIDGET_H

#include "nehewidget.h"

#include <gl/GLU.h>
#include <QKeyEvent>

nehewidget::nehewidget(QWidget *parent,bool fs)
: QGLWidget(parent)
{
zoom=-0.0;
tilt=90.0;
spin=0.0;
loop=0;
twinkle=false;

fullscreen=fs;
setGeometry(100,100,640,480);
//	setCaption("OpenGL window"); //这个函数，不支持了吧？
setWindowTitle("OpenGL Window");
if(fullscreen) showFullScreen();

startTimer(5);
}

nehewidget::~nehewidget()
{

}

void nehewidget::initializeGL()
{
loadGLTextures();
glEnable(GL_TEXTURE_2D);

glShadeModel(GL_SMOOTH);
glClearColor(0,0,0,0);
glClearDepth(1.0);
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LEQUAL);
glHint(GL_PERSPECTIVE_CORRECTION_HINT,GL_NICEST);

//	glBlendFunc(GL_SRC_ALPHA,GL_ONE);
//	glEnable(GL_BLEND);
for(loop=0;loop<num;loop++) {
star[loop].angle=0.0;
star[loop].dist=((float)loop)/num*1.5;
star[loop].r=rand()%256;
star[loop].g=rand()%256;
star[loop].b=rand()%256;
}
}

void nehewidget::paintGL()
{
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
glBindTexture(GL_TEXTURE_2D,texture[0]);
for(loop=0;loop<num;loop++) {
glLoadIdentity();

glTranslatef(0.0,0.0,zoom);
glRotatef(tilt,1.0,0.0,0.0);
glRotatef(star[loop].angle,0.0,1.0,0.0);
glTranslatef(star[loop].dist,0.0,0.0);
glRotatef(-star[loop].angle,0.0,1.0,0.0);
glRotatef(-tilt,1.0,0.0,0.0);

if(twinkle) {
glColor4ub(star[(num-loop)-1].r,star[(num-loop)-1].g,star[(num-loop)-1].b,255);
glBegin(GL_QUADS);
glTexCoord2f(0.0,0.0);glVertex3f(-0.01,-0.01,0.01);
glTexCoord2f(1.0,0.0);glVertex3f(0.01,-0.01,0.01);
glTexCoord2f(1.0,1.0);glVertex3f(0.01,0.01,0.01);
glTexCoord2f(0.0,1.0);glVertex3f(-0.01,0.01,0.01);
glEnd();
}
glRotatef(spin,0.0,0.0,1.0);
glColor4ub(star[loop].r,star[loop].g,star[loop].b,255);
glBegin(GL_QUADS);
glTexCoord2f(0.0,0.0);glVertex3f(-0.01,-0.01,0.01);
glTexCoord2f(1.0,0.0);glVertex3f(0.01,-0.01,0.01);
glTexCoord2f(1.0,1.0);glVertex3f(0.01,0.01,0.01);
glTexCoord2f(0.0,1.0);glVertex3f(-0.01,0.01,0.01);
glEnd();

spin+=0.01;
star[loop].angle+=((float)loop)/num;
star[loop].dist-=0.01;
if(star[loop].dist<0.0) {
star[loop].dist+=1.5;
star[loop].r=rand()%256;
star[loop].g=rand()%256;
star[loop].b=rand()%256;
}
}
}

void nehewidget::timerEvent(QTimerEvent *)
{
updateGL();
}

void nehewidget::resizeGL(int w,int h)
{
if(h==0) h=1;
glViewport(0,0,(GLint)w,(GLint)h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
//下面这个函数在Qt和OpenGL新版本中都不支持了！先注释掉吧，以后不得不用时再想办法
//	gluPerspective(45.0,(GLfloat)w/(GLfloat)h,0.1,100.0);

glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}

void nehewidget::keyPressEvent(QKeyEvent *e)
{
switch(e->key()) {
case Qt::Key_T:
twinkle=!twinkle;
updateGL();
break;
case Qt::Key_PageUp:
zoom-=0.2;
updateGL();
break;
case Qt::Key_PageDown:
zoom+=0.2;
updateGL();
break;
case Qt::Key_Up:
tilt-=0.5;
updateGL();
break;
case Qt::Key_Down:
tilt+=0.5;
updateGL();
break;
case Qt::Key_F2:
fullscreen=!fullscreen;
if(fullscreen) showFullScreen();
else {
showNormal();
setGeometry(100,100,640,480);
}
updateGL();
break;
case Qt::Key_Escape:
close();
}
}

void nehewidget::loadGLTextures()
{
QImage tex,buf;
if(!buf.load("texture.bmp")) {
qWarning("Please use single-color instead");
QImage dummy(128,128,QImage::Format_RGB32);
dummy.fill(Qt::red);
buf=dummy;
}
tex=QGLWidget::convertToGLFormat(buf);
glGenTextures(1,&texture[0]);
glBindTexture(GL_TEXTURE_2D,texture[0]);
glTexImage2D(GL_TEXTURE_2D,0,3,tex.width(),tex.height(),0,GL_RGB,GL_UNSIGNED_BYTE,tex.bits());
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_NEAREST);
}